1. Field of the Invention
The present invention pertains to methods for preventing reovirus recognition in the treatment of cellular proliferative disorders, and particularly ras-mediated cellular proliferative disorders, in mammals. In particular, the methods provide for reovirus treatment of immunosuppressed or immunodeficient mammals to treat the proliferative disorders. Immunosuppression, immunoinhibition or otherwise inducing an immunodeficient state in a mammal renders the reovirus more effective. The methods may include the selective removal of immune constituents that may interfere with the systemic delivery of the virus; preventing reovirus recognition by the host immune system; and removal of the virus from an immune suppressed or immune incompetent host following treatment with reovirus.
2. References
The following publications, patent applications and patents are cited in this application:
U.S. Pat. No. 5,023,252
Armstrong, G. D. et al. (1984), Virology 138:37
Aronheim, A., et al.,(1994) Cell, 78:949-961
Barbacid, M., Annu. Rev. Biochem., 56:779-827 (1987)
Berrozpe, G., et al. (1994), Int. J. Cancer, 58:185-191
Bischoff, J. R. and Samuel, C. E., (1989) Virology, 172:106-115
Bos, J. (1989) Cancer Res. 49:4682
Cahill, M. A., et al., Curr. Biol., 6:16-19 (1996)
Chandron and Nibert, xe2x80x9cProtease cleavage of reovirus capsid protein mu1 and mu1C is blocked by alkyl sulfate detergents, yielding a new type of infectious subvirion particlexe2x80x9d, J. of Virology 72(1):467-75 (1998)
Chaubert, P. et al. (1994), Am. J. Path. 144:767
Cuff et al., xe2x80x9cEnteric reovirus infection as a probe to study immunotoxicity of the gastrointestinal tractxe2x80x9d Toxicological Sciences 42(2):99-108 (1998)
Der, S. D. et al., Proc. Natl. Acad. Sci. USA 94:3279-3283 (1997)
Dudley, D. T. et al., Proc. Natl. Acad. Sci. USA 92:7686-7689 (1995)
Duncan et al., xe2x80x9cConformational and functional analysis of the C-terminal globular head of the reovirus cell attachment proteinxe2x80x9d Virology 182(2):810-9 (1991)
Fields, B. N. et al. (1996), Fundamental Virology, 3rd Edition, Lippincott-Raven
Gentsch, J. R. K. and Pacitti, A. F. (1985), J. Virol. 56:356
E. Harlow and D. Lane, xe2x80x9cAntibodies: A laboratory manualxe2x80x9d, Cold Spring Harbor Laboratory (1988)
Helbing, C. C. et al., Cancer Res. 57:1255-1258 (1997)
Hu, Y. and Conway, T. W. (1993), J. Interferon Res., 13:323-328
James, P. W., et al. (1994) Oncogene 9:3601
Laemmli, U. K., (1970) Nature, 227:680-685
Lee. J. M. et al. (1993) PNAS 90:5742-5746
Lee, P. W. K. et al. (1981) Virology, 108:134-146
Lee, P. W. K. et al. (1999) Reovirus for the Treatment of Neoplasia, PCT International Application No. PCT/CA98/00774
Levitzki, A. (1994) Eur. J. Biochem. 226:1
Lowe. S. W. et al. (1994) Science, 266:807-810
Lyon, H., Cell Biology, A Laboratory Handbook, J. E. Celis, ed., Academic Press, 1994, p. 232
Mah et al., xe2x80x9cThe N-terminal quarter of reovirus cell attachment protein sigma 1 possesses intrinsic virion-anchoring functionxe2x80x9d Virology 179(1):95-103 (1990)
McRae, M. A. and Joklik, W. K., (1978) Virology, 89:578-593
Millis, N E et al. (1995) Cancer Res. 55:1444
Mundschau, L. J. and Faller, D. V., (1992) J. Biol. Chem., 267:23092-23098
Nagata, L., et al., (1984) Nucleic Acids Res., 12:8699-8710
Paul R. W. et al. (1989) Virology 172:382-385
Raybaud-Diogene. H. et al. (1997) J. Clin. Oncology, 15(3):1030-1038
Remington""s Pharmaceutical Sciences, Mace Publishing Company, Philadelphia Pa. 17th ed. (1985)
Robinson, M. J. and Cobb, M. H., Curr. Opin. Cell. Biol. 9:180-186 (1997)
Rosen, L. (1960) Am. J. Hyg. 71:242
Sabin, A. B. (1959), Science 130:966
Samuel, C. E. and Brody, M., (1990) Virology, 176:106-113
Smith, R. E. et al., (1969) Virology, 39:791-800
Stanley, N. F. (1967) Br. Med. Bull. 23:150
Strong, J. E. et al.,(1993) Virology, 197:405-411
Strong, J. E. and Lee, P. W. K., (1996) J. Virol., 70:612-616
Trimble, W. S. et al. (1986) Nature, 321:782-784
Turner and Duncan, xe2x80x9cSite directed mutagenesis of the C-terminal portion of reovirus protein sigma1:evidence for a conformation-dependent receptor binding domainxe2x80x9d Virology 186(1):219-27 (1992)
Waters, S. D. et al., J. Biol. Chem. 270:20883-20886 (1995)
Wiessmuller, L. and Wittinghofer, F. (1994), Cellular Signaling 6(3):247-267
Wong, H., et al., (1994) Anal. Biochem., 223:251-258
Yang, Y. L. et al. EMBO J. 14:6095-6106 (1995)
Yu, D. et al. (1996) Oncogene 13:1359
All of the above publications, patent applications and patents are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent application or patent was specifically and individually indicated to be incorporated by reference in its entirety.
3. State of the Art
Normal cell proliferation is regulated by a balance between growth-promoting proto-oncogenes and growth-constraining tumor-suppressor genes. Tumorigenesis can be caused by genetic alterations to the genome that result in the mutation of those cellular elements that govern the interpretation of cellular signals, such as potentiation of proto-oncogene activity or inactivation of tumor suppression. It is believed that the interpretation of these signals ultimately influences the growth and differentiation of a cell, and that misinterpretation of these signals can result in neoplastic growth (neoplasia).
Genetic alteration of the proto-oncogene Ras is believed to contribute to approximately 30% of all human tumors (Wiessmuller, L. and Wittinghofer, F. (1994), Cellular Signaling 6(3):247-267; Barbacid, M. (1987) A Rev. Biochem. 56, 779-827). The role that Ras plays in the pathogenesis of human tumors is specific to the type of tumor. Activating mutations in Ras itself are found in most types of human malignancies, and are highly represented in pancreatic cancer (80%), sporadic colorectal carcinomas (40-50%), human lung adenocarcinomas (15-24%), thyroid tumors (50%) and myeloid leukemia (30%) (Millis, N E et al. (1995) Cancer Res. 55:1444; Chaubert, P. et al. (1994), Am. J. Path. 144:767; Bos, J. (1989) Cancer Res. 49:4682). Ras activation is also demonstrated by upstream mitogenic signaling elements, notably by tyrosine receptor kinases (RTKs). These upstream elements, if amplified or overexpressed, ultimately result in elevated Ras activity by the signal transduction activity of Ras. Examples of this include overexpression of PDGFR in certain forms of glioblastomas, as well as in c-erbB-2/neu in breast cancer (Levitzki, A. (1994) Eur. J. Biochem. 226:1; James, P. W., et al. (1994) Oncogene 9:3601; Bos, J. (1989) Cancer Res. 49:4682).
Current methods of treatment for neoplasia include surgery, chemotherapy and radiation. Surgery is typically used as the primary treatment for early stages of cancer; however, many tumors cannot be completely removed by surgical means. In addition, metastatic growth of neoplasms may prevent complete cure of cancer by surgery. Chemotherapy involves administration of compounds having antitumor activity, such as alkylating agents, antimetabolites, and antitumor antibiotics. The efficacy of chemotherapy is often limited by severe side effects, including nausea and vomiting, bone marrow depression, renal damage, and central nervous system depression. Radiation therapy relies on the greater ability of normal cells, in contrast with neoplastic cells, to repair themselves after treatment with radiation. Radiotherapy cannot be used to treat many neoplasms, however, because of the sensitivity of tissue surrounding the tumor. In addition, certain tumors have demonstrated resistance to radiotherapy and such may be dependent on oncogene or anti-oncogene status of the cell (Lee. J. M. et al. (1993) PNAS 90:5742-5746; Lowe. S. W. et al. (1994) Science, 266:807-810; Raybaud-Diogene. H. et al. (1997) J. Clin. Oncology, 15(3):1030-1038). In view of the drawbacks associated with the current means for treating neoplastic growth, the need still exists for improved methods for the treatment of most types of cancers.
The present invention is directed to the enhancement of the effectiveness of existing reovirus therapies in the treatment of proliferative disorders.
This invention pertains to methods for preventing reovirus recognition in the treatment of cellular proliferative disorders, and particularly ras-mediated cellular proliferative disorders, in mammals. The mammal may be selected from dogs, cats, sheep, goats, cattle, horses, pigs, mice, humans and non-human primates. The method comprises suppressing or otherwise inhibiting the immune system of the mammal and, concurrently or subsequently, administering to the proliferating cells an effective amount of one or more reoviruses under conditions which result in substantial lysis of the proliferating cells. In particular, the methods provide for reovirus treatment of immunosuppressed or immunodeficient mammals to treat the proliferative disorders. Immunosuppression, immunoinhibition or otherwise inducing an immunodeficient state in a mammal renders the reovirus more effective. The methods may include the selective removal of immune constituents that may interfere with the systemic delivery of the virus; preventing reovirus recognition by the host immune system; and removal of the virus from an immune suppressed or immune incompetent host following treatment with reovirus. Alternatively, reovirus may be administered to a mammal with a diminished immune response system under conditions which result in substantial lysis of the proliferating cells. Immune systems may be compromised by one or more of the following: an HIV infection; as a side effect of chemotherapy or radiation therapy; by selective removal of B and/or T cell populations; by removal of antibodies (anti-antireovirus antibodies or all antibodies), and the like.
The immunosuppression or immunoinhibition may be accomplished by means of an immunosuppressant, an immune suppressive agent, or by any other means which inhibits a mammal""s immune system or renders the mammal immunodeficient. When an immunosuppressant is used, it may be administered prior to or concurrent with reovirus administration. The mammal should be rendered immunosuppressed, immunodeficient or immunoinhibited prior to or concurrent with reovirus administration.
The reovirus may be a mammalian reovirus or an avian reovirus. The reovirus may be modified such that the outer capsid is removed, the virion is packaged in a liposome or micelle or the proteins of the outer capsid have been mutated. The reovirus and/or immunosuppressive agent can be administered in a single dose or in multiple doses. The proliferative disorder may be a neoplasm. Both solid and hematopoietic neoplasms can be targeted. The immunosuppression results in more effective reovirus treatment.
Accordingly, in one aspect the invention provides a method of treating a ras-mediated proliferative disorder in a mammal, comprising the steps of:
a) performing a step selected from the group consisting of:
i) administering to the proliferating cells in said mammal an effective amount of an immune suppressive agent;
ii) removing B-cells or T-cells from said mammal;
iii) removing anti-reovirus antibodies from said mammal;
iv) removing antibodies from said mammal;
v) administering anti-antireovirus antibodies to said mammal; and
vi) suppressing the immune system of the mammal; and
b) administering to the proliferating cells in said mammal an effective amount of one or more reoviruses under conditions which result in substantial lysis of the proliferating cells.
Also provided is a method of treating a ras-mediated neoplasm in a human, comprising suppressing or otherwise compromising the immune system of the mammal and, concurrently or subsequently, administering to the neoplasm a reovirus in an amount sufficient to result in substantial oncolysis of the neoplastic cells. The reovirus may be administered by injection into or near a solid neoplasm.
Also provided is a method of inhibiting metastasis of a neoplasm in a mammal, comprising suppressing or otherwise compromising the immune system of the mammal and, concurrently or subsequently, administering to the mammal a reovirus in an amount sufficient to result in substantial lysis of the neoplastic cells.
Also provided is a method of treating a suspected ras-mediated neoplasm in a mammal, comprising surgical removal of the substantially all of the neoplasm, suppression or other inhibition of the immune system of the mammal and, administration of an effective amount of reovirus at or near to the surgical site resulting in oncolysis of any remaining neoplastic cells.
Also provided is a pharmaceutical composition comprising an immunosuppressant or an immunoinhibitant such as an anti-antireovirus antibody, a reovirus, and a pharmaceutically acceptable excipient.
Kits comprising a reovirus and another component such as an immune suppressive agent, means for removing B-cells or T-cells from a mammal, means for removing anti-reovirus antibodies from a mammal, means for removing antibodies from a mammal, anti-antireovirus antibodies and means for suppressing the immune system of the mammal are also provided.
Also provided is a pharmaceutical composition comprising an immunosuppressant or immunoinhibitant, a modified reovirus and a pharmaceutically acceptable excipient.
The methods and pharmaceutical compositions of the invention provide an effective means to treat neoplasia, without the side effects associated with other forms of cancer therapy. Inhibition or suppression of the immune system increases the availability of reovirus to infect and lyse ras-mediated proliferating cells because anti-reovirus antibodies are not formed. Because reovirus is not known to be associated with disease, any safety concerns associated with deliberate administration of a virus are minimized.